Analysis and assessment of 1.5℃ target

The Paris Agreement was adopted at the 21th Conference of Parties (COP21) in December 2015 in Paris (UNFCCC, 2015). The Paris Agreement sets a long-term temperature goal of holding the global average temperature increase to well below 2 C and pursuing efforts to limit the temperature increase to 1.5 C above pre-industrial levels. As only a few study has been conducted for the assessment of 1.5C so far, COP21 requested IPCC to prepare special reports on impacts of the 1.5C target and its pathway until 2018. With this request, IPCC decided to prepare special reports tat its plenary session in April 2016.

In this report we analyzed emissions reduction costs and measures for realizing 1.5C target, with assuming multiple pathways considering various uncertainty.

The result implies that realizing 1.5C target is difficult in reality, because there are large differences between the emission pathway until 2030 estimated based on the submitted NDCs and most of the emission pathways that are consistent with the 1.5 C target assumed here. Emission pathways to limit global warming to 1.5C by 2300 are at the level of being consistent with emission pathways by 2030, but enormous amounts of global net negative emissions are required continuously from the middle of this century to 2300, that may lead to the conclusion that the possibility of realizing the target is extremely small.